Thermostatic device



Aug. 7, 1934. w. J. sMlTH 1,969,240

THERMOSTATIG DEVICE i Filed NOV. 23, 1933' f INVENTOR. MYa/J//jz A TT ORNEYS.

Patented Aug. 7, l1934 4 UNITEDv STATES PATENT OFFICE 1,969,240' 'rnEaMosTa'ric DEVICE william J. smith, Riverside, a. I.

Application November 23, 1933, Serial No. 699,348

'z claims. (C1. zas-1oz) may be mounted in the hot air chamber of a fur`` 'Ihis invention relates to a thermostatic device; and has for one of its objects the provision of a means for multiplying the movements of the heatresponsive, relatively-movable elements of the thermostatic device, whereby certain factors in effecting the desired results may be nicely controlled.

Another object of the invention is the provision of a multiplying device which is particularly adaptable for the regulation of a combustion furnace where it is desired to maintain the heat conditions substantially uniform.

Another object of the invention is the provision of a simple but effective multiplication by the arrangement of levers so mounted that they can be moved in opposite. directions by one of the relatively movable elements.

Another object of the invention is the provision of a control for hot air furnaces, which may be inexpensively made and installed for use.

With ythese and other objects in view, the invention consists of certain novel features of construction, as will be more fully described, and particularly pointed out in the appended claims.

In the accompanying drawing:

Fig. 1 is a side elevation of a furnace showing my thermostatic control as associated therewith.

Fig. 2 is an elevation of one of the levers which are used.

Fig. 3 is an elevation of the other lever.

Fig. 4 is an end view of the levers in assembled relation, showing the pulleysmounted thereon as in alignment and also showing the abutting relation of the surfaces of the levers.

35 l Fig. 5 is a sectional view thru the device and the support therefor in the hot air header of the furnace.

Fig. 6 is a sectional view thru the relatively expandible element of the device..

40 Fig. 7 is a sectional view of the device thru the support tube for the device.

Fig. 8 is a perspective view of the member secured to the end of the relatively expandible element.

Fig. 9 is a sectional view illustrating one of the levers as mounted in its tube.

Fig. lois a. sectional view of the other lever f mounted in thev tube.

There are relatively few heat control devices 50 on the market which are adaptable for use in a hot air chamber or header of a hot air furnace in controlling the operation of the heat conditions of the furnace at this location; also relatively few devices for multiplying small movements in a thermostatic device, which are adaptable for such use; and in order that a simple construction may be provided for such a need or in other locations for which it maybe adapted, I have provided a pair of elements which are relatively movable in `reference to changes in heat conditions, which nace and which are provided with simple means for effectively multiplying such a movement so that the draft can be nicely controlled for the combustion chamber in such a furnace, or other factors may be controlled by-which the -amount of combustion may be regulated; and the following is a more detailed description of the present embodiment of this invention illustrating the preferred means by which these advantageous results may be accomplishedz- With reference to the drawing, 15 indicates a hot air furnace having a flue pipe 16, ash pit opening 17 controlled by a valve or door 18 which will regulate the draft to a suilicient extent to control a coal fired furnace.' In dotted lines at 19, I have indicated a baille plate and above this there is a chamber 20 containing heated air for the rooms of some building or other use. In this hot air chamber, I have supported my thermostatic device` which I will designate generally 21.

This thermostatic device consists of two elements of differently expandible materials. One of the elements 22 is an aluminum tube which has a high coelcient of expansion. 'I'his aluminum tube is iixedly secured to a sleeve 23 constituting a part of this element, which sleeve is threaded as at 24 to be screwed into an opening 25 in the wall 26 of the furnace and in order that this element may be supported at its inner end 27, I have provided a tube 28 having a pin 29 fixed in this end of the tube by means of the body portion 30 held in by the end of the tube in any suitable manner, such asA the locking pin 31, the pin 29 extending into an opening32 in the diametrically opposite wall 33 of the furnace. This supporting tube 28 is of substantially the length across the furnace leaving sumcient space at its ends for expansion-and serves-as a means for holding up and supporting the inner end of the relatively expandible element 22.

Within the tubular expandible element 22, I provide the element 35 which is relatively nonexpandible consisting of a so'called pyrex rod altho invar steel may be used or some other material having a practically negligible coefcient of expansion. This rod engages a plug 36 threaded into the end of the tube 22 to form an abutment for it at one end, while the opposite end of this rod engages a slidable member 37 which is mounted within the sleeve 23. One end surface 38 of this member is adapted for' engagement with the end of the rod 35, while a slot 39 is adapted to receive a screw 40 to prevent rotation of the member in the sleeve 23. The other end of this member is reduced to provide a central point 4l which will engage a pair of levers 42 and 43 to move these levers upon relative movement of the tube 22 and the rod 35,' the levers 42 and 43 being Apivotally ,mountedin the sleeve 23.

The lever 42 ts within a slot 44 of a size substantially the width of the lever while this lever I also fits within a diametrically opposite slot 45 in the sleeve which is of a length greater than the width ofthe lever and in order that the lever may not pass thru the slots so formed, I have provided an abutment 46 to engage the outer surface 47 of the sleeve and support the lever in this position. This lever is thus restricted in movement in the slot 44 providing substantially a pivotal.

point while permitting movement in the slot 45 for the swinging of the same. Lever 43 is mounted in the slot 48 which is of a width substantially the width'of the lever 43 and is also located in 5 the diametrically opposite slot 49 of a length greater than the width of the lever. By reason of the narrow slot 48, the lever is substantially pivoted at this location in the sleeve, while its lower end is permitted a relative freedom of move- 0 ment. The slots for the two levers adjoin and together form an opening substantially in the shape of a T.

The levers are also provided with projections 52 and 53, each of which contacts with the inner surface of the opposite lever to provide a rubbing or bearing point of engagement which assists in the movement of these levers back and forth one on the other. Each of the levers is offset as at 54 and 55 so as to provide for the alignment of the pair of pulleys 56 and 57 on the lever 43 with a' single pulley 58 on the lever 42 over which a chain or other flexible element 60 which extends thru the door 61 to some notch or hook for adjustment, is trained rst over the pulleys 5'7, thence over Lpulley 58 and thence over pulley 56 to. be-dropped down to the draft control 19, whereby the weight of the draft will tend to mbve the levers into parallelism and thus there is exerted at the point 41 a pressure tending -to force the rod 45 against 4Q rits abutment in the end of the tube 22.

As the tube 22 elongates by reason of heat there is permitted a movement of the non-expandible rod 35, inwardly, and the levers may be then moved toward substantially parallel relation to ldrop the door 18 and shut oil the draft and as the fire will then be diminished, there will be a cooling and as this cooling occurs the tube 22 will contract and tend to force the rod 35 outwardly against thek levers to cause them to pivot about their pivotal points and move the pulleys in opposite directions away from each other to raise the door y184 and permit an entrance of air to increase the draft and consequently the re in the furnace.

By reason of my levers and by their arrangement I am enabled to multiply the amount of movement of the relatively expandible andnonexpandible elements to an extent such as desired by the length of the levers and at the same time I provide sufhcient power todo considerable work by reason of the expandible force of the elements utilized.-

I have described my invention particularly as connected-with a hot air furnace but it will be 6.5'greadily understood thatthe thermostatic controls may beA applied in various other uses to -which the inventiony will readily apply itself.

1 'I'he foregoing description is directed solely to i wards the construction illustrated, but I desire it to be understood that I reserve the privilege of resorting to all the mechanical changes to which the device is susceptible, the invention being dened and limited only' by the terms of the appended claims.

I claim:

1. In a thermostatic device, a pair 4oi.' adjacent levers, one pivoted at its end andthe other pivoted at a point spaced from its end, and a relatively movable element engaging said levers at a point between said pivots whereby said levers are moved in opposite directions.

2. In a thermostatic device, a sleeve provided with lever receiving slots therein at diametrically opposite points, the slot at, one point for one lever being of a length substantially the width of the lever and at the other point being of a length longer than the lever and the slot being reversely dimensioned for the ,other lever,l whereby said levers pivot about diametrically opposite points of said sleeve to move their free ends in opposite directions.

3. In a thermostatic device, a sleeve provided with a lever receiving slot of a dimension to substantially fit the lever and permit swinging movement thereof at this point as a pivot and a slot in the sleeve at a point diametrically oppositel` of a dimension to permit longitudinalmovement 100 of said lever, a lever in said slots, and means to engage the sleeve adjacent the slot and support the lever in desired position.

4. In a thermostatic device, two relatively movable elements, a pair of adjacent levers, one of said 105 elements engaging both levers and the other element providing a pivotal support for both levers, the arrangement of the .pivots being such that one lever is pivoted on one side of the point of engagement and the other lever is pivoted on the other side of the point of engagement, whereby the levers move in opposite directions, and means operated by the movement of said levers to actuate a factor toward accomplishing the desired result.

5.' In a thermostatic device, two relatively movable elements, and a pair of levers mounted to be actuated by said relative movement in opposite directions, whereby a multiplicity of said relative movements is erected, pulleys on said le- 120 vers and a flexible member trained over said pulleys, whereby the relative movement is translated into a longitudinal movement.

6. In a thermostatic device, two relatively movableelements, and a pair of levers mounted .to beactuated by said relative movement in opposite directions, whereby a multiplication of said relativemovements is effected, two pulleys on one lever and one on the other lever, a flexible member trained over said pulleys, said levers being shaped to dispose said pulleys in a single plane. f

'7. In a thermostatic device, two relatively movlable elements comprising a tube and a rod in the tube, said tube having diametrically located oppositely disposed T-shaped slots, a pair of levers having one portion located in the narrower stem of said slot and the other portion located in the relatively elongated head thereof, whereby the levers are pivoted above andbelow the center of said tube, said rod being provided with a portion to engage said levers at the center of said tube and move them in oppositedirections, and means operable by said levers to actuate a factor for effecting the desired change.

WILLIAM J. sm'm. 

